Putting Theory Into Practice

The ideal is to limit the points in a system at which gain or attenuation is applied to two; One gain at the input, and one attenuation before the power amplification. This minimizes the possibility of poor signal to noise ratio in your system.

Metering

Meters tell you the level of your audio, usually the color red indicates clipping, or that you're approaching clipping.

In Scratch Live there are two meters, one for each deck. There are also three gain controls, one for each deck individually as well as one master gain affecting both sets of outputs equally. They indicate the level of each output just before the signal is sent to your hardware. If the meters are sitting just below the red, your signal is as loud as it can be without clipping. This is generally what you will want.

Track Gain Tags

Each audio file in your library can have a gain value associated with it. If you have files which are too quiet, or too loud, you can correct this using the track gain knob in Scratch Live, and that setting will be saved into the gain tag.

In Scratch Live 1.7 we introduced an Auto Gain feature, which does this step automatically. Check it out in the manual.

SSL Master Gain

If your tracks peak just under maximum level, the master gain in Scratch Live should remain at 12'oclock.

Do not be tempted to crank the master gain "into the red" to get some more level into your mixer; all you will be doing is clipping your audio, distorting the music before it even exits your computer.

It should be noted that the track and master gains inside Scratch Live make up a single overall SSL gain (or attenuation) value for each deck's output. So in practice you should set your SSL master gain so most of the tracks in your library are just below clipping on the SSL meters, and then adjust individual tracks as needed to bring them to the right level.

Mixer Input Gains

In the signal flow diagram, you can see some other sources coming into the mixer, normal vinyl from a turntable, and CDs. Your input gains on the mixer are a good place to even up different sources.

Use the input gains in conjunction with the meters on your mixer to make sure the loudest track you will play doesn't clip the mixer at all.

As usual, get it into the yellow or orange, not the red.

Mixer Channel Faders

With correctly set input gains and master output on your mixer, the channel faders should purely be a tool to add dynamics to your performance, and aid in smoothly transitioning between tracks. You should be able to have your track faders all the way up without distorting or going into the red on your mixer's output meters.

Mixer Master Output Gain

Even though it's being mentioned last, you should try and set the mixer master output gain first thing when you're setting up, or during sound check.

Play the loudest track in your playlist, set the input gain into the mixer so it's not clipping internally, then set the master output gain to the loudest level you're going to hit during you're set - or to the specifications of the sound technician (if you have that luxury)